Prince's First Music Teacher: 'He Was at the Band Room Door at 8 a.m. Sharp Every Day Waiting to Be Let In'

Musical genius Prince died April 21 at the age of 57. Subscribe now for an inside look into his private life and shocking death, only in PEOPLE.

Former Bryant Junior High music teacher Jimmy Hamilton vividly recalls having Prince Rogers Nelson, the “shy, smart” kid he taught piano, in his class in the early 1970s.

“He was a seriously smart kid, and he just got music,” Jimmy Hamilton, 79, tells PEOPLE. “He really understood it, what music was at the core. Even from that early age.”

But Hamilton says he “had no idea” Prince would go on to become one of the world’s most beloved musicians.

“I thought he would achieve success as a local musician, because he was a natural musician, he had the ear,” he says. “But he was so shy, nothing like the persona he put on while on stage.

“It still baffles me thinking that the smart kid in my class would go on to become the Minnesota king of funk.”

The former music teacher, who had Prince in his seventh and eighth grade business of music and music theory classes at Minneapolis’ Bryant Junior High, describes the icon as being “introverted” – until he picked up an instrument, that is.

“He was extremely quiet, but when he played music it just seemed like he was a different person altogether,” says Hamilton. “His eyes would light up when he started performing.”

Prince also spent an hour before class each morning jamming with friends in a band practice room.

“He was at the band room door at 8 a.m. sharp every day waiting to get let in,” recalls Hamilton. “After, I would go in and break up the session and make the kids go to biology class.”

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Hamilton says Prince was mostly “self-taught,” so the two focused on music theory and learning fun, contemporary songs.

“He was an easy student, he was so eager to learn and it came naturally to him. He could play any instrument, but the song we worked on the most was ‘Stairway to Heaven’ on the piano,” says Hamilton with a laugh. “He loved that one!”